This proposal is a continuation of previous work where the rate of protein synthesis was described in mature ovarian oocytes, unfertilized and fertilized laid Drosophila eggs. The nature of of the lesion found in the oocyte will be investigated. Specific steps of the mechanism of initiation of protein synthesis will be assayed. A biochemical screen of known female-steriles will be instituted, looking for stage-specific development mutants that effect protein synthesis. It is anticipated that mutant analysis will provide the basis for probing the organisms, regulatory and developmental mechanisms.